The literal meaning of the word eiruv is “mixing.” Onkelos translates the verse “Lo sizra karmecha kilayim” as “la tizra karmach eiruvin.”
This term is used for several halachic concepts.
Chazal teach that one of the 39 avos melachah prohibited on Shabbos is the prohibition of hotzaah—carrying items from one domain to another. Likewise, it is forbidden to carry objects within the public domain for a distance of four amos (approximately two meters) or more.
An eiruv is the halachic mechanism that enables carrying—meaning transporting and moving objects—on Shabbos in the public area and from one domain to another. Without an eiruv, one may not go out into the street with objects, strollers, children, etc., which prevents most people, especially families with children, from leaving the house to visit, stroll, or pray.
The halachic act called eiruv is carried out by constructing physical partitions or halachic partitions that enclose the area within which carrying is to be permitted.
Regarding carrying from one domain to another, we distinguish between four domains: reshus harabim, karmelis, reshus hayachid, and makom patur. Reshus harabim is a place where a very large number of people pass daily and which meets specific criteria. Reshus hayachid is any area enclosed by partitions and measuring four by four tefachim (32 cm). A karmelis is an area that is neither reshus harabim nor reshus hayachid.
Most open areas today are classified as karmelis. The eiruv encloses the karmelis with partitions and turns these areas into a reshus hayachid.
Today, the most common method of constructing an eiruv is by stretching a thin, taut wire carried on poles. This type of eiruv is a halachic partition that forms a tzuras hapesach—two “doorposts” with a “lintel.”
Hilchos eiruv contain many halachic and practical details. Many eiruvin are constructed in ways that do not meet the basic halachic requirements. Furthermore, an eiruv may develop various issues, such as the wire tearing. If this occurs and the wire snaps, the entire eiruv becomes invalid, and once the wire tears, carrying becomes forbidden—whether transferring objects between domains or carrying within reshus harabim for four amos or more.
The term eiruv is also used for additional halachic subjects, such as:
For further details, see the glossary of terms.
